If you need a theoretical exploration of the grammar of graphics and its use with ggplot2, see a ggplot2 grammar guide.
The geom pile on is a suppliment to the ggplot grammar guide and shows you a lot of “geoms” that you can use to communicate about your data. Piling up the geoms allows you to see how plot types relate to one another.
ggplot themes takes you through logic of the ggplot2 theme adjustments.
For examples of data wrangling/manipulation with pipelines and pipes (%>%), check out The Tidyverse in Action.
geom_sf gives you an example of using geom_sf with ggplot to create coordinate plots and choropleths.